Using multiple criteria to find a WebElement in Selenium

No it does not. You cannot concatenate/add selectors like that. This is not valid anyway. However, you can write the selectors such a way that will cover all the scenarios and use that with findElements()

By byXpath = By.xpath("//input[(@id='id_Start') and (@class = 'blabla')]")
List<WebElement> elements = driver.findElements(byXpath);

This should return you a list of elements with input tags having class name blabla and having id id_Start

To combine By statements, use ByChained:

driverChrome.findElements(
    new ByChained(
        By.tagName("input"),
        By.id("id_Start"),
        By.className("blabla")
    )
)

However if the criteria refer to the same element, see @Saifur's answer.